Hydrogel Based on Chitosan/Gelatin/Poly(Vinyl Alcohol) for In Vitro Human Auricular Chondrocyte Culture.

Three-dimensional (3D) hydrogels provide tissue-like complexities and allow for the spatial orientation of cells, leading to more realistic cellular responses in pathophysiological environments. There is a growing interest in developing multifunctional hydrogels using ternary mixtures for biomedical applications. This study examined the biocompatibility and suitability of human auricular chondrocytes from microtia cultured onto steam-sterilized 3D Chitosan/Gelatin/Poly(Vinyl Alcohol) (CS/Gel/PVA) hydrogels as scaffolds for tissue engineering applications. Hydrogels were prepared in a polymer ratio (1:1:1) through freezing/thawing and freeze-drying and were sterilized by autoclaving. The macrostructure of the resulting hydrogels was investigated by scanning electron microscopy (SEM), showing a heterogeneous macroporous structure with a pore size between 50 and 500 µm. Fourier-transform infrared (FTIR) spectra showed that the three polymers interacted through hydrogen bonding between the amino and hydroxyl moieties. The profile of amino acids present in the gelatin and the hydrogel was determined by ultra-performance liquid chromatography (UPLC), suggesting that the majority of amino acids interacted during the formation of the hydrogel. The cytocompatibility, viability, cell growth and formation of extracellular matrix (ECM) proteins were evaluated to demonstrate the suitability and functionality of the 3D hydrogels for the culture of auricular chondrocytes. The cytocompatibility of the 3D hydrogels was confirmed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reaching 100% viability after 72 h. Chondrocyte viability showed a high affinity of chondrocytes for the hydrogel after 14 days, using the Live/Dead assay. The chondrocyte attachment onto the 3D hydrogels and the formation of an ECM were observed using SEM. Immunofluorescence confirmed the expression of elastin, aggrecan and type II collagen, three of the main components found in an elastic cartilage extracellular matrix. These results demonstrate the suitability and functionality of a CS/Gel/PVA hydrogel as a 3D support for the auricular chondrocytes culture, suggesting that these hydrogels are a potential biomaterial for cartilage tissue engineering applications, aimed at the regeneration of elastic cartilage.

Remaining microtia tissue as a source for 3D bioprinted elastic cartilage tissue constructs, potential use for surgical microtia reconstruction.

The absence of ears in children is a global problem. An implant made of costal cartilage is the standard procedure for ear reconstruction; however, side effects such as pneumothorax, loss of thoracic cage shape, and respiratory complications have been documented. Three-dimensional (3D) printing allows the generation of biocompatible scaffolds that mimic the shape, mechanical strength, and architecture of the native extracellular matrix necessary to promote new elastic cartilage formation. We report the potential use of a 3D-bioprinted poly-ε-caprolactone (3D-PCL) auricle-shaped framework seeded with remaining human microtia chondrocytes for the development of elastic cartilage for autologous microtia ear reconstruction. An in vivo assay of the neo-tissue formed revealed the generation of a 3D pinna-shaped neo-tissue, and confirmed the formation of elastic cartilage by the presence of type II collagen and elastin with histological features and a protein composition consistent with normal elastic cartilage. According to our results, a combination of 3D-PCL auricle frameworks and autologous microtia remnant tissue generates a suitable pinna structure for autologous ear reconstruction.

Resultado quirúrgico y calidad de vida en reconstrucción auricular autóloga. Hospital General Dr. Manuel Gea González. México / Surgical outcomes and quality in autologous auricle reconstruction. Hospital General Dr. Manuel Gea González. México

INTRODUCCIÓN Y OBJETIVO: La microtia es un problema estético que conlleva una afección psicosocial en el desarrollo del paciente. La reconstrucción auricular mediante injerto costal autólogo es el procedimiento más usado. Determinamos los resultados quirúrgicos en nuestro hospital y el impacto en la calidad de vida de los pacientes con microtia sometidos a reconstrucción auricular con cartílago costal autólogo. MATERIAL Y MÉTODO: Estudio observacional, descriptivo, transversal y prolectivo en pacientes con diagnóstico de microtia uni o bilateral 1 año después de la reconstrucción. Evaluamos el resultado quirúrgico mediante cuestionario desarrollado y publicado por la primera autora, calificando características de apariencia estética de la oreja. Evaluamos la calidad de vida del paciente mediante cuestionario Glasgow Benefit Inventory, versión validada al español, en mayores de 15 años; para pacientes pediátricos utilizamos cuestionario Glasgow's Children's Benefit Inventory, versión traducida y validada por traductor especializado. RESULTADOS: Recogimos 83 pacientes con edad de 8 a 46 años. En la evaluación quirúrgica 13 pacientes (15.6%) tuvieron un resultado excelente, 27 (32.5%) bueno, 29 (34.9%) regular y 14 malo (16.8%). En la evaluación de calidad de vida encontramos en la escala total puntuación positiva en 78 pacientes (93.9%) y negativa en 5 (6%). CONCLUSIONES: El estudio presenta un panorama objetivo de las expectativas del cirujano sobre satisfacción y bienestar del paciente. Si bien solo encontramos resultados buenos y excelentes en el 48%, al revisar la escala de satisfacción encontramos puntaciones positivas, con bienestar en casi el 94%. Es importante que los pacientes conozcan nuestra preocupación por saber el impacto de la intervención y que podamos retroalimentar nuestra práctica quirúrgica. Hasta donde sabemos, este es el primer estudio en México que evalúa ambos aspectos

BACKGROUND AND OBJECTIVE: Microtia is not only an aesthetic problem but involves patient psychosocial development. The gold standard for auricular reconstruction is autologous costal cartilage. Our aim is to evaluate surgical outcomes and impact in quality of life after auricular reconstruction with autologous costal cartilage in microtia patients at our hospital. METHODS: Observational, descriptive, cross an prolective study on patients with uni or bilateral microtia 1 year after auricular reconstruction procedure. Surgical outcome was evaluated with a method previously published by the first author evaluating auricular aesthetic characteristics. Quality of life was evaluated with Glasgow Benefit Inventory, validated in Spanish, for over 15 years old patients; for pediatric patients we used the Glasgow's Children's Benefit Inventory, in a validated translated version. RESULTS: The study group was composed by 83 patients from 8 to 46 years old. Surgical outcome were excellent in 13 cases (15.6%), good in 27 (32.5%), regular in 29 cases (34.9%) and bad in 14 (16.8%). Quality of life had a positive total score in 78 cases (93.9%) and negative in 5 (6%). CONCLUSIONS: The study allows us an objective overview of surgeon's expectations regarding patient satisfaction and well-being. Although we only found good and excellent results in 48% of the patients, when reviewing the satisfaction scale we found positive scores in almost 94%. It`s important that patients know our concern about the impact of our intervention and to provide feedback on our surgical practice. As far as we know, this is the first study in Mexico evaluating both aspects

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Estudio epidemiológico del trauma de pabellón auricular en el Hospital General Dr. Manuel Gea González, México / Epidemiological study of auricle trauma at Hospital General Dr. Manuel Gea González, México

Introducción y Objetivo: La posición expuesta del pabellón auricular lo predispone a una gran cantidad de lesiones. Su reconstrucción tras amputación traumática o laceración requiere una evaluación cuidadosa y experiencia en reconstrucción auricular para lograr un resultado exitoso. El tratamiento temprano de este tipo de lesiones previene la cicatrización defectuosa y por lo tanto mejores condiciones para una reconstrucción estética. El objetivo del presente estudio es conocer la población más afectada por el trauma del pabellón auricular y su etiología en nuestro medio. Material y Método: Realizamos un estudio retrospectivo de pacientes diagnosticados de trauma del pabellón auricular atendidos por la División de Cirugía Plástica y Reconstructiva del Hospital General Dr. Manuel Gea González de la Ciudad de México (México), durante un período de 5 años, con un total de 214 pacientes. Resultados: Dada la especial exposición del pabellón auricular en varones que usan pelo corto, la proporción en cuanto a sexo fue 4.5:1 en nuestra serie. La edad más frecuente fue los 33 años; entre los 0 y 40 años se encontró el 82% de los pacientes, con un promedio de 26 años de edad. El lado izquierdo fue el más afectado (54.6% de los casos). La mayoría de las lesiones fueron, de acuerdo a la clasificación de Weerda, de grado I (abrasiones o heridas sin compromiso del cartílago), con un 37.8% de los casos, seguidas por las de grado IV (lesiones por avulsión con pérdida de segmento o amputación total) con pérdida de cartílago en el 35.5%. El mecanismo más frecuente fue un traumatismo directo seguido por la mordedura humana. El área anatómica más afectada fue el hélix, seguramente por ser la estructura más externa. No hubo ningún caso candidato a reimplante. Conclusiones: Este trabajo nos permitió establecer el grupo de edad más afectado en nuestro medio por trauma auricular, así como las principales causas del mismo. Aportamos también 2 casos de lesión iatrogénica en pabellón auricular en pacientes pediátricos que nos ayudaran a prevenir o evitar dichas complicaciones El 59.3% de los casos se debió a riñas o agresión por tercera persona, cifra que refleja la problemática social de nuestro país

Background and Objective: The anatomical localization or the auricles make them susceptible of trauma. Reconstruction after traumatic amputation requires a careful evaluation and experienced surgeon in auricle reconstruction for a good result. Early treatment of this kind of lesions avoids pathologic wound healing and gets proper conditions for auricle reconstruction. The objective of our study is to know which is the most affected population by auricle trauma and the etiology of this lesions in our area. Methods: We realized a retrospective study analyzing clinical and photographic files of the patients attended by auricle trauma in a 5 years period at Hospital General Dr. Manuel Gea González in the City of México (México): a total of 214 patients. Results: Because of the exposed localization of the auricle in males with short hair, we found a rate 4.5:1 male/female in our study. The most frequent age was 33 years and 82% of the patients were between 10 and 40 years old, with a media of 26 years old. Left side was involved in 54.6%. Concerning Weerda classification 37.8% cases were I degree (wounds without cartilage compromise) followed by 35.5% cases in IV degree (avulsion with certain degree of cartilage lost). The most frequent mechanism of injury was by direct trauma followed by human bite. The most frequent localization was the helix that could be explained by being the most external part of the auricle. None of our patients were reimplantation candidate. Conclusions: Our study let us establish the most frequently affected age group in our area by auricle trauma, and its main etiology. Besides, we report two cases of iatrogenic auricle lesion in pediatric patients than can help us to prevent or avoid these complications. In our series, 59.3% of the cases was due to fights or aggressions for a third person, that reflect the social problematic in our country

Biocompatibility of human auricular chondrocytes cultured onto a chitosan/polyvynil alcohol/epichlorohydrin-based hydrogel for tissue engineering application / Biocompatibilidad de condrocitos humanos cultivados sobre un hidrogel a base de quitosano/alcohol polivnílico/epiclorhidrina para aplicación en ingeniería de tejidos

Tissue engineering (TE) has become an alternative for auricular reconstruction based on the combination of cells, molecular signals and biomaterials. Scaffolds are biomaterials that provide structural support for cell attachment and subsequent tissue development. Ideally, a scaffold should have characteristics such as biocompatibility and bioactivity to adequate support cell functions. Our purpose was to evaluate biocompatibility of microtic auricular chondrocytes seeded onto a chitosan-polyvinyl alcohol-epichlorohydrin (CS-PVA-ECH) hydrogel to propose this material as a scaffold for tissue engineering application. After being cultured onto CS-PVA-ECH hydrogels, auricular chondrocytes viability was up to 81%. SEM analysis showed cell attachment and extracellular matrix formation that was confirmed by IF detection of type II collagen and elastin, the main constituents of elastic cartilage. Expression of elastic cartilage molecular markers during in vitro expansion and during culture onto hydrogels allowed confirming auricular chondrocyte phenotype. In vivo assay of tissue formation revealed generation of neotissues with similar physical characteristics and protein composition to those found in elastic cartilage. According to our results, biocompatibility of the CS-PVA-ECH hydrogel makes it a suitable scaffold for tissue engineering application aimed to elastic cartilage regeneration.

La ingeniería de tejidos (TE) es una alternativa para la reconstrucción auricular basada en la combinación de células, señales moleculares y biomateriales. Los andamios fabricados con biomateriales brindan un soporte estructural que favorece la adhesión cellular y el desarrollo del tejido. Un andamio debe poseer características como biocompatibilidad y bioactividad para soportar adecuadamente funciones celulares. Nuestro objetivo fue evaluar la biocompatibilidad de condrocitos auriculares de microtia cultivados sobre un hidrogel a base de quitosano-alcohol polivinílico-epiclorhidrina (CS-PVA-ECH) y proponerlo como andamio con aplicaciones en ingeniería de tejidos. La viabilidad de los condrocitos auriculares es superior al 81% después de ser cultivados sobre el hidrogel. El análisis por SEM reveló la unión celular y formación de matriz extracellular sobre el hidrogel; confirmada mediante detección por IF de colágena tipo II y elastina. La expresión de marcadores moleculares durante la expansión in vitro y el cultivo sobre los hidrogeles confirmaron el fenotipo condral. El ensayo de formación de tejido in vivo demostró la generación de neotejidos con características físicas y composición similar al cartílago elástico. Nuestros resultados indican que la biocompatibilidad del hidrogel de CS-PVA-ECH lo hace un andamio adecuado para aplicaciones en ingeniería de tejidos enfocadas a regeneración de cartílago elástico.

Lack of IgG antibody seropositivity to Borrelia burgdorferi in patients with Parry-Romberg syndrome and linear morphea en coup de sabre in Mexico.

BACKGROUND: Progressive hemifacial atrophy or Parry-Romberg Syndrome (PRS) is a rare, acquired, progressive dysplasia of subcutaneous tissue and bone characterized by unilateral facial involvement. Its etiology is unknown, but theories about its pathogenesis include infectious, degenerative, autoimmune, and traumatic causes among others. The causal relationship of PRS and linear morphea en coup de sabre (LMCS) with Borrelia burgdorferi infection remains controversial. Our goal was to serologically determine anti-B. burgdorferi antibodies in patients diagnosed with PRS and LMCS to establish a possible association as a causative agent. METHODS: We conducted a serology study with patients belonging to a group of 21 individuals diagnosed with PRS, six with LMCS, and 21 matched controls. Anti-Borrelia IgG antibodies were determined by ELISA. A descriptive statistical analysis and Fischer's exact test were done. RESULTS: In serological tests, only two cases had borderline values and were further analyzed by Western blot with non-confirmatory results. For both the PRS and LMCS group, the association test was not significant, suggesting a lack of association between PRS or LMCS and the presence of anti-Borrelia antibodies. CONCLUSION: In Mexico there are no previous studies on Borrelia infection and its relationship between PRS or LMCS. Our result showed a lack of association of either clinical entities with anti-Borrelia-antibodies. Former reports of this association may suggest coincidental findings without causal relationship.

Keloid skin scars: the influence of hyperbaric oxygenation on fibroblast growth and on the expression of messenger RNA for insulin like growth factor and for transforming growth factor.

Wound healing can result in the development of keloid scars that contain atypical fibroblasts and an overabundance of extracellular matrix components. Hyperbaric oxygenation (HBO) refers to exposure to pure oxygen under increased atmospheric pressure and is recognized as a valuable supplementary method of treatment for problematic wounds. The effect of HBO in the expression of insulin-like growth factor type 1 (ILGF-1) and transforming growth factor ß (TGF-ß) messenger RNAs was determined by semiquantitative RT-PCR in fibroblasts obtained from keloid scars and nonwound involved skin fibroblast from the same patient. ILGF-1 and TGF-ß are the principal mitogens during wound regeneration. We found a decrease in the growth of fibroblasts and in the expression of ILGF-1 and TGF-ß messengers in keloid and nonkeloid fibroblast after chronic exposition to hyperbaric oxygenation compared with normal oxygen partial pressure.

Bilateral sciatic nerve axonotmesis after gluteal lipoaugmentation.

The number of lipoaugmentation procedures, and specifically the number of gluteal lipoaugmentations, has risen dramatically over the past decade. Though gluteal lipoaugmentation confers a pleasing hourglass profile with seemingly minimal risk, its risks have not been fully realized. We report the case of a healthy 35-year-old woman who suffered axonotmesis of the sciatic nerve due to direct lipoinjection into and around the nerve sheath. She was treated expectantly in our Peripheral Nerve Clinic for 3 months without evidence of improvement. Subsequently, she underwent internal and external neurolysis. Eighteen weeks after her neurolysis, she continues to demonstrate signs of severe peripheral neuropathy, but has begun to show signs of nerve regeneration. This is the first reported case of sciatic nerve axonotmesis due to gluteal lipoaugmentation. It highlights the importance of a thorough knowledge of gluteal anatomy and a consciousness of the risks involved with lipoaugmentation of deep structures.